Arctic Blast Set to Arrive on Thanksgiving; Dangerous Wind Chills, Lake Effect Snow, Severe Thunderstorms

A significant arctic outbreak will arrive in the northern Rockies and northern Plains on Thanksgiving into Friday and advance farther south and east through much of the Plains and Midwest this weekend. Dangerous wind chill temperatures are expected with a significant long duration lake effect snow event possible downwind of the Great Lakes. Severe thunderstorms may be possible in the Southeast. Read More >

Hurricane or Tropical Storm

Biggest takeaway:
Most think WIND when they think of hurricanes & tropical storms. However, they are actually FOUR threats combined –

Rain Flooding
Tidal Flooding/Storm Surge
Wind
Tornadoes

Warning/Trigger for Plan:
NWS Hurricane or Tropical Storm Watch or Warning (issued only for the wind threat)
The other threats are covered by watches & warnings from your planning sections above on flooding, tornadoes, and tidal flooding.

Advance Notice/Time to Activate & Accomplish Your Planned Response:
A Watch is typically issued 24-72 hours in advance of the wind threat.
A Warning is typically issued 12-24 hours in advance of the wind threat.
The other threats are covered by watches & warnings from your planning sections above on flooding, tornadoes, and tidal flooding.

Frequency:
* A landfalling hurricane in the Mid Atlantic is very rare (once in every 50 – 100 years on average). It has been decades for us. When it does occur again, and we get our “Sandy”, it will be truly devastating to the region - and unlike anything we remember in our lifetimes.
* Having a remnant of a former tropical storm or hurricane passing over the Mid Atlantic is much more common, about 0-2/year on average. Flooding is the most common threat with these, but the other 3 threats should not be discounted, and should be monitored.

How Accurate Warnings?
* Hurricane and Tropical Storm Warnings and Watches continue to get even more accurate. Forecasting the track/path of the storm is particularly accurate. The range of possibilities of the track of the center of the storm (not the extent of the impacts) is denoted by the “error cone” typically shown with the track forecast. Intensity forecasting (how strong the winds will be) is reasonably accurate, but you should allow for 1 category higher wind speeds than forecast in your planning.

No two hurricanes/tropical storms are the same. Just because you experienced one, don't think that the impacts will be anywhere near the same the next time.
Whether landfalling full strength in your region, or a remnant of a storm that made landfall days before, these always have the potential of FOUR threats. Each storm has its own variety of threat levels from each of these four. Some storms are big on floods, low on winds. While some are big tornado producers. It is best to monitor these at our tropical page, where the caliber of these threats are each discussed for each storm. The four potential threats are:
- Rain Flooding
  - See above section on flooding, and use your flood plan.
- Wind
  - See above section on extreme winds, and use your extreme wind plan.
- Tornados
  - See above section on tornadoes, and use your tornado plan.
- Tidal Flooding (if applicable)
  - See above section on tidal flooding, and use your tidal flooding plan.
  - Note that extreme tides from hurricanes (not winds) are often the deadliest threat by far for those that live along or near tidal shores. Most of the 2,000+ deaths from Katrina were from storm surge/tidal flooding. The same was true for the majority of the dozens who lost their lives in Sandy around New York.
  - Of course this is a non-threat (at least directly) to any location over 20' above sea level.
- Safety References: